3-Star Strategy

Shoot the first Red Bird at the Stone on top of the second Corporal Pig. The stone debris should hit the TNT below, killing the first two Corporal Pigs. Shoot the second Red Bird at the second TNT, killing the third Corporal Pig. Shoot the Yellow Bird at the TNT under the fourth Corporal Pig, so that it is killed, and the Foreman Pig is killed by the force of the explosion.